The use of centrifugal pumps in petroleum wells increases the production flow. However, when centrifugal pumps are utilized in wet completion well installations, the cost of intervention for maintenance is high. Specifically, maintenance of the centrifugal pump requires: i) interruption of production of the well, ii) retrieval of the production column, pump and accessories of the well, and iii) the use of a probe for maintenance of the pump. In many cases these items represent an obstacle, not only with regard to production profits, but also with respect to the production process.
Brazilian Application No. PI 0400926-6 entitled “Subsea Pumping Module System and Installation Method of the Same” describes an alternative configuration in which a pumping unit is installed in an auxiliary or dummy well, where it is easier to retrieve the pumping unit for maintenance. However, because it is necessary to construct this auxiliary or dummy well, the cost of production is higher. Even construction of a hollow pile may represent an increase in costs.
U.S. Pat. No. 6,508,308 (hereinafter U.S. '308) describes multi-stage methods for production in a wellhead, which includes fluid pumps operated sequentially during the life of the well. In the embodiments described in U.S. '308, the production column is bifurcated into a pair of legs. One of the legs includes a first fluid pump which may be actuated in a selective manner to facilitate fluid flow through that leg. A sliding glove and a flapper valve diverter are also provided to block production flow through that leg or the other leg to permit the selective use of the first fluid pump.
Thus, U.S. '308 discloses production systems that can produce oil without removing the production column from the well. The described systems include a “Y”-shaped block assembly with two legs. The “Y”-shaped block is suspended at the lower end of a production column. One of the legs supports a first fluid pump.
The first fluid pump, which is positioned within the production column, is used until it ceases operation. Then, the second fluid pump is introduced into the production column with the assistance of coiled tubing. The fluid is thereafter lifted to the surface using the second fluid pump. This eliminates the need to remove the production column from the well to replace the first fluid pump. When the second fluid pump ceases to operate, it may be easily removed from the well and replaced without the time and costs associated with removing the production column from the well.
Despite the technological advances in the art, there continues to be a need for a subsea petroleum production system that may be installed and recovered by cable. Such a production system is described and claimed in this application.